The Effects of Parathyroid Extract Upon Incorporation of 1-14C-Glucosamine Into Bone

The radioactivity in bone, kidney, liver, serum protein and uncalcified connective tissue was determined after administration of 1-14C-glucosamine to adult rats. The experimental animals were pretreated 1-3 days with parathyroid extract. Significant increases in specific radioactivity were noted in bone, kidney and serum protein of the rats treated with parathyroid extract. Radioactivity of liver and uncalcified connective tissue was not significantly changed by parathyroid extract. Sialoprotein and chondroprotein isolated from bone were both radioactive. The specific radioactivity of both fractions increased in the animals treated with parathyroid extract; however, as little radioactivity was found in galactosamine, it may be concluded that the increase is due largely to glycoprotein biosynthesis and not to increased synthesis of mucopolysaccharide.